{"cve":"CVE-2011-4415","nvd":{"published":"2011-11-08T11:55:05.850","modified":"2026-06-16T23:34:53.160","status":"Modified","description":"The ap_pregsub function in server/util.c in the Apache HTTP Server 2.0.x through 2.0.64 and 2.2.x through 2.2.21, when the mod_setenvif module is enabled, does not restrict the size of values of environment variables, which allows local users to cause a denial of service (memory consumption or NULL pointer dereference) via a .htaccess file with a crafted SetEnvIf directive, in conjunction with a crafted HTTP request header, related to (1) the \"len +=\" statement and (2) the apr_pcalloc function call, a different vulnerability than CVE-2011-3607.","cvss_v4":null,"cvss_v3":null,"cwes":["CWE-20"],"references":["http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c03360041","http://www.gossamer-threads.com/lists/apache/dev/403775","http://www.halfdog.net/Security/2011/ApacheModSetEnvIfIntegerOverflow/","http://www.halfdog.net/Security/2011/ApacheModSetEnvIfIntegerOverflow/DemoExploit.html","http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c03360041"],"products":["apache:http_server"],"source":"nvd","synced_at":"2026-10-19T19:59:31.623151214+00:00"},"epss":{"cve":"CVE-2011-4415","score":0.03019,"percentile":0.87444,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}